Herpes Simplex and Herpes Zoster are both caused by viruses, but they are very different. These viruses belong to a large family of DNA viruses known as Herpesviridae. They are capable of causing latent, or recurring, episodes and are known for life-long infection. They will be discussed separately.
Herpes Simplex, also known as “cold sore” or “fever blister,” is a viral infection that occurs most often around mucous membranes, such as the lips or genitals, but it can occur anywhere on the body. It is transmitted by touch, including kissing or sexual contact as well as simple contact with infected material (such as a shared glass or silverware).
Herpes Simplex infections appear as red, grouped, watery blisters which crust up and are often painful or itchy. They usually persist for 1-2 weeks per outbreak and always recur at the same site. Patients usually notice a prodrome such as stinging or soreness at the site prior to the eruption. Patients frequently feel ill and may have a fever during the initial episode. Also, the initial episode often takes three weeks to heal. With the passage of time, the duration between outbreaks lengthens and the infection usually become milder.
Oral Herpes (HSV-I) is contagious up to a day before it appears and until the lesion has visibly resolved. Genital Herpes (HSV-II) is contagious even if there are no signs or symptoms. Therefore, it is possible to transmit the virus to a sexual partner without any sign of an outbreak. It is estimated that 80% of Americans have been exposed to and carry the herpes simplex virus.
Treatments include oral and/or topical antiviral prescription medications. When the oral anti-virals are taken at the onset of symptoms, even before a visible lesion appears, they may avert a breakout or lessen its intensity. Maintenance dosing is available for prevention and to avoid spreading both oral and genital herpes.
Herpes Zoster is caused by another herpes virus responsible for Chickenpox and Shingles. The first exposure to the Herpes Zoster virus results in Chickenpox, an itchy rash characterized by small blisters with redness around them beginning on the torso and extending over the rest of the body. After the chickenpox rash resolves, the virus travels to the dorsal root ganglions (collections of nerve tissue at the base of the spine), where it remains until reactivation. Later in life, typically when under stress, the herpes zoster virus is reactivated. It travels along a specific nerve and appears as a unilateral rash. It is often ”shingles.” Chicken pox is disappearing in the younger population due to immunization early in life.
Shingles normally presents as a visible rash of red, grouped blisters that follow a specific nerve only on one side of the body. It does not cross the midline. It can be preceded or accompanied by pain. The pain (resulting from nerve damage) can last months or longer, is often very severe, and is referred to as “post-herpetic neuralgia.” The incidence of post-herpetic pain is more prevalent in older patients.
Prevention can be achieved with the Zostavax immunization.
Treatment of acute infections usually includes an oral anti-viral prescription medication, topical medications, and pain treatment when necessary. Injections of very low dose triamcinolone under the eruption speed healing and can diminish the severity of post-herpetic neuralgia.